Middlings-purifier



(No Model.) I 2 SheetsSheet 1. W. D. GRAY.

MIDDLINGS PURIFIBR.

No. 428,674. Patented May 2'7, 1890.

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W. D. GRAY. MIDDLINGS PURIPIER.

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UN TED STATES PATENT ()FFICE.

WVILLIAM D. GRAY, OF MILYVAUKEE, WISCONSIN.

MlDDLlNGS-PURIFIER.

SPECIFICATION forming part of Letters Patent No. 428,674, dated May 27,1890.

Application filed December 21, 1887. Serial No. 258,599. (No model.)

To aZZ whom it may concern:

Be it known that I, WILLIAM D. GRAY, of Milwaukee, in the county ofMilwaukee and State of lVisconsin, have invented certain new and usefulImprovements in Middlings- Purifiers, of which the following is aspecification. 4

My invention relates to middlings-purifiers; and it consists infeatures, combinations, and details hereinafter described.

In the accompanying drawings, Figure l is a longitudinal verticalsection of a purifier embodying my improvements; Fig. 2, a vert1caltransverse section on the line cc to of Fig. 1; Fig. 3, face and edgeviews of the adj ustable plate or hanger in which the lower shaft of theelevator is carried at each end.

So far as the purifier itself independent of the aspirating attachmentis concerned the construction may be more or less varied, the inventionbeing applicable to various styles of machine, but being moreparticularly designed for use'in connection with the purifier known tothe trade as the Reliance Purifier, manufactured by E. P. Allis (K? 00.,of Milwaukee, WVisconsin.

It is well known to millers and others that a considerable amount ofcoarse middlings tails over with the bran and coarser impurit-ies fromthe shaking sieve or screen, and heretofore it has been customary toreturn the tailings to rolls or other reducing machinery for furtherreduction. Such treatment, however, involves the colnminution of thebran and the intimate mingling of the bran particles and otherimpurities with the middlings thus reduced, thereby rendering.

extremely difficult the subsequent operation of separating the middlingsfrom the mass.

The passage of the coarse niiddlings over the tail of the sieve with theimpurities is inevitable, for the reason that if the cloth be madesufiiciently coarse to permit the coarser middlings to fall through aconsiderable amount of bran and impurities will likewise pass throughthe sieve; hence the clothing of the sieve must be fine enough toexclude these foreign matters, and consequently fine enough to preventthe coarse middlin gs from falling through.

By my invention the tailings are subjected to the action ofair-currents, which effectually separate the coarse middlings from thebran and impurities and deliver said middlings into the conveyer-trough,which receives the fine middlings falling through the sieve, or to anysuitable receptacle, and discharges the bran and impurities into thefailings-trough or from the machine.

Referring to the drawings, A represents the casing of the machine; B,the shaking sieve or screen frame clothed in the usual manner; 0, thetailingsspout, through which the bran, coarse middlings, and othermatters which fail to pass through the meshes of the sieve aredelivered.

D indicates the air-trunk at the top of the machine, through which theair is drawn from the casing by a fan U, and E and F indicate theconveyer-troughs, into which the middlings and the bran or impuritiesare delivered, said troughs being provided with conveyers G and II forremoving the materials therefrom.

I indicates the aspirating attachment as a whole, which is preferably soconstructed that it may be applied directly to purifiers alreadymanufactured and in use. This attachment consists, essentially, of acasing provided with an elevator trunk or chamber J, containing anendless bucket-elevator K, which is so located with reference to thetailings-spout O as to receive the material discharged therefrom andcarry it upward to the top of a hopper L, and a series of inclinedshelves or boards M, over which the material gravitates as it flows fromthe hopper, being subjected in its travel to currents of air, whichcarry off the lighter particles and permit the middlings to fall into aspout provided for them.

As shown in Fig. 1, the hopper L is provided with a gravitating valve orgate a, which serves to prevent the air from being drawn down throughthe elevator-trunk and into the body of the chest A. Opposite theinclined face of each shelf M is placed an upright board or guard N,provided with a secondary inclined shelf M, the upright boards forming,together with the depending portions of the shelves M, a series of shortvertical trunks, through which the material falls in passing from oneshelf to another, during which fall it is acted upon by currents of airpassing across the heads or upper edges of the respective shelves and upthrough said trunks.

D indicates an air'trunk connecting with the interior of theaspirating-chamber I in rear of the inclined shelves M M,and which mayopen into the trunk D of the main machine or sieve-purifier A, or maypass to a separate fan provided especially for the aspiratingattachment, this being a question of judgment and con vcnience nota'lfecting the invention herein described. The strength of theair-current through the aspirator is regulated and controlled by a valve0 at the top of the aspirating-chamber, as seen in lrig. l. The materialwhich travels over and falls from the shelves or boards M is deliveredinto a spout P, which is represented as opening into the conveyor-troughE, which receives the purified middlin which fall through the sieve 15of thesicve-puriiier. The light dust and impurities are drawn outwardfrom the shelves or boards M by the force of the air-current and causedto pass either through the air-trunk D or to fall from one shelf M toanother and to be delivered finally into a trunk Q, which maycommunicate with the convcyerspout F or may open out of the machine todischarge the heavy impurities into any suitable receptacle.

In order to simplify the construction of the machine as far aspracticable, the conveyortroughs E and F are extended or prolongedbeyond the rear end of the casing A and made to serve for both the mainbody of the machine and the aspirating attachment, as indicated in Fig.1, though this is not essential, as separate troughs and conveyors mightbe employed.

The elevator K consists, preferably, of two endless separable linkchains carrying buckets formed of hard-wood strips grooved or madeconcave on their carrying-faces, the chains passing aboutsprocket-wheels carried by an upper driving-shaft R and a lower shaft S.For the purpose of permitting proper adjustment of the lower shaft S itis carried in vertically-adjustable boxes or bearings of the form shownin Fig. 3thatis to say, in sleeves or boxes I), which are cast integralwith plates T, which are provided with elongated eyes 0 to receive thefastening bolts or screws (1, by which the plates are secured to theside walls of the aspirating-chamber I. These sleeves or boxes extendinto or through slots c, form ed in the side walls of theaspiratirig-chamber, and thus prevent the lateral movement ofthe boxesand the shaft S, which is carried in them. The particular form ofelevatorshown and described is not, however, essential, it being obviousthat any convenient or usual form of elevator may be substituted.

Motion may be imparted to the shaft R by belt V, passing about pulleys fand g, respectively secured on the shaft R and the shaft of fan U; ormotion may be taken from any other convenient moving part of themachine.

The casing of the asphating-chamber I is formed with air-inlets atsuitable points to permit the free passage of air across the fallingstreams of material between the hopper L and the spouts P Q.

5 g indicate cleats formed or secured upon the sides of theaspirator-chamber for convenient attachment to the rear end of thepurifier-casing A.

It is designed to construct this attachment with special reference tomachines already sold and in use; but it may obviouslybc built as anintegral part of new machines.

It has been customary from the earliest construction and use ofmiddlings-puriiicrs to subject the material tailing over the sieve tothe action of a current of air, or, in other words, to so arrange thefan and the ducts communicating therewith as to cause au upward currentof air past the end or tailot the sieve. This action, though somewhatbeneficial, is wholly inadequate for effecting thorough aspiration ofthe tailings, and will not secure the results sought and attained by me.The material. which, passes over the end of the sieve consists of coarsemiddlings and tailings, and the aspirator acts as a coarse-middlingspurifier, effecting a complete separation of the coarse middlings andthe t-ailings. \Vhen the aspirator is combined with and made a part ofthe purifier, (utilizing thereby the same fan and the same conveyors andconveyer-troughs,) the miller is enabled to clothe the sieve line enoughto insure clean middlings passing through the cloth and to cause thecoarser middlings containing the impurities to pass over the tail of themove. The aspirator acting upon the materials thus tailing over thesieve takes out the impurities, thereby making a separation into twoproductsone poor enough for feed and the other in excellent condition togo to the rolls or other reducing apparatus. In speaking of theaspirator, therefore, I do not mean to be understood as referring to orincluding a mere trunk or spout extending from the tail of the sieve tothe fan, but a structure in which the material tailing over the sieve iscaused to fall in a sheet or stream from one shelf or su rface toanother successively, subject to acrosscurrent of air at each fall orpassagc from shelf to shelf, whereby perfect aspiration s insuredv andcomplete removal of impurities is effected.

The employment of the elevator to carry the material to the top of themachine enables me to secure a sufficient fall to subject the materialto the repeated action of the air-current without unduly lengthening themachine and without increasing its height.

I laving thus described my invention, what I claim is 1. In amiddlings-puritier, the combination of a casing and sieve or screen, aspout to receive the failings of the screen, an elevator located inposition to receive the tailin gs from said spout, a hopper arranged toreceive the IIO material carried up by the elevator, a series ofinclined shelves or boards beneath the hopper, an air-trunkcommunicating with the sieve-chamber and shelf-chamber 0f the easing',and a fan communicating with the trunk, and serving to cause a currentof air through the sieve and between the boards and shelves, the sieve,elevator, or shelves being arranged within one casing.

2. In combination with the casing and sieve or screen ofamiddling's-purifier, an aspirating attachment arranged, substantiallyas shown, to receive the tailings from the sieve and provided withdischarge-spouts P Q, one communicating with the middlings-trough andthe other with the tailings-trough of the cars ing A.

3. In combination with the casing -A and sieve B of amiddlings-purifier, middlingstrough E and tailings-trough F, extendingalong the lower part of said casing and projecting beyond the same, andan aspirating attachment 1, provided with discharge-spouts P and Q,communicating, respectively, with the troughs E F.

4. In combination with the casing A and sieve B of a middlings-purifier,an aspirating attachment consisting of a casing I, provided withelevator-trunk J and elevator K, hopper L, inclined boards M M, spouts PQ to receive the material from said inclined boards or shelves, a fan,and an air-trunk communicating with the casing I and with the fan, allsubstantially as shown and described.

5. In a middlings-pnrifier, the combination of a casing divided into twochambers, a sieve located in one of said chambers, an aspirator, ahopper at the head of the aspirator, and an elevator located between thetail of the sieve and the hopper in the second of said chambers, a fan,an air-trunk communicating with both of the chambers of the casing, anda conveyer-trough and conveyer, also common to both chambers.

In witness whereof I hereunto set my hand in the presence of twoWitnesses.

\VILLIAM D. GRAY.

Witnesses:

B. T. LINZARDER, RICHARD HOPPIN.

